The design was achieved in part by placing the driver in the center of the cab. The steering wheel is flanked by LCD screens--in place of conventional gauges--and there is a sleeping compartment directly behind the driver's pod.

The WAVE features a range-extended electric powertrain, consisting of a Capstone micro-turbine and an electric motor.

To reduce weight, the entire truck is made of carbon fiber--including the trailer trailer is made from carbon fiber.

Walmart says this is the first example of a carbon-fiber trailer ever produced, and that its 53-foot side panels are the first single pieces of carbon fiber that large that have ever been manufactured.

Like the tractor, the trailer was also designed for optimum aerodynamic efficiency. It features a convex nose, which not only reduces aerodynamic drag but has the added of benefit of increasing cargo space in the trailer.

Walmart says the carbon-fiber trailer is around 4,000 pounds lighter than a conventional one, allowing a truck to carry more freight without the need for increased power or fuel consumption.

The retail giant did not reveal any plans to produce the WAVE, and in fact it would be highly unlikely to get into the truck business.

But it's far from the only company encouraging ways to make big trucks more efficient.